Japanese Laid-Open Patent Publication No. 2015-69857 discloses a display device including pixels each including a light emitting element formed of an organic electroluminescence (hereinafter, referred to as “organic EL”) material. In this display device, a protective layer covering an organic EL layer is used as a sealing film. The protective layer includes a plurality of insulating layers (three layers of inorganic insulating layer/organic insulating layer/inorganic insulating layer) provided in a stacked manner.
Among the plurality of insulating layers, which are provided on a top surface of the organic EL layer, the inorganic layers are formed by sputtering and the organic layer is formed by application. Therefore, the plurality of insulating layers are provided in a pixel region (display region) and also extend to a terminal region (non-display region) of the display device. For this reason, on the region of each of connection terminals in the terminal region, the insulating layers need to be in a removable state and the connection terminals need to be in a conductive state.
The insulating layers may be removed from the terminal region by dry etching or wet etching. However, in order to remove the insulating layers including the inorganic insulating layer/organic insulating layer/inorganic insulating layer provided in a stacked manner, etching conditions suitable to the respective insulating layers need to be set. This involves problems that, for example, the manufacturing process is complicated, the margin is reduced, the tact time is increased, and in some cases, a plurality of processing chambers may be needed.